Classroom Discussion Activity

Invasive Species

It’s war in many ecosystems around the world as invasive and native species battle for primacy. Facing the increased exchange of ship ballast water among worldwide ports, biologists are grappling with a rate and scale of alien takeovers unprecedented in history. In this Bio Bulletin, see the mussels and crayfish that are stressing the vast freshwater network of the Great Lakes region, and learn what researchers are doing to give native populations a leg up.

Class Discussion

Establish prior KnowledgeBefore watching the video discuss invasive species with students. Ask them to describe the ways invasive species colonize new habitats and how they might affect the ecology and economy of those areas. Tell them that over 120 invasive species are threatening the ecology of the Great Lakes. In this video, scientistsa re collecting data on these species in hopes of finding an effective way of controlling them.

Exploration
Have students view the Feature and read the synopsis. Ask students to take notes while they are watching the video about the species scientists are studying and their hypotheses about how they might be eliminated. Divide the class into three teams. Assign one of the invasive species to each team to read and report on. Have each team answer the following questions:.
• How did the species get to the Great Lakes Region?
• How does the species disrupt the ecosystem and economy?
• What is being done to stop or eliminate the species?
Quagg and zebra Mussels
http://www.great-lakes.net/teach/pollution/ans/ans_2.html
http://www.wwmt.com/news/great_1345016___article.html/lakes_says.html
Rusty Crayfish
http://www.biopoint.com/rustywebpage/rustywebpage.html
http://www.sciencedaily.com/releases/2006/08/060828074913.htm
Asian Carp
http://www.epa.gov/glnpo/invasive/asiancarp/http://www.glc.org/announce/06/07wrda.html

Wrap-up
When groups are ready, have them report their findings to the rest of the class. Use the following question to wrapup the activity:• What might be the next step for scientists if their methods for eliminating invasive species are not effective?